2017-08-10T19:39:23ZShape changing composite material design for interactionshttp://hdl.handle.net/1721.1/109657
Shape changing composite material design for interactions
Yao, Lining
This thesis is about designing shape change composite material for interactions. Interaction has gone beyond computer screens and electronics to enter the realm of physical materials. Shape changes at the micro level will cause shape changes and other physical property changes at the macro level. A design strategy for bioinspired shape-changing composite materials includes two development steps: a shape-changing material unit (SCMUnit), followed by a shape-changing matrix composite (SCMC). SCMC contains the matrix phase and the dispersion phase, one of which is composed of SCMUnits. In addition, SCMC can be hierarchical, while SCMC and SCMUnits have a relationship of recursive embodiment. Two major projects exemplify how water-responsive shape-changing material can be used to design interactions based on the outlined design strategy. bioLogic is about hygromorphic bacteria-based SCMC, while Transformative Appetite is about water-driven edible SCMC material. Programmable transformations, multilayer composites and sequential-foldings were engineered with these materials. A customized fabrication strategy, combining wet lab processes and additive manufacturing, was introduced, while applications were presented to exemplify various interaction scenarios. In addition, the SCMC design strategy has been adapted to develop shape-changing materials beyond water responses. Stimuli and responsive behaviors are used to categorize these materials. A design space for nature-inspired responsive material design for shape-changing interfaces was outlined from two aspects: the technical aspects and the conceptual aspects. The technical aspects are identified with the interplays of three features of nature: natural structural mechanisms, natural stimuli and natural transformation mechanisms. The conceptual aspects is summarized in two conceptual spaces: microscale shape changes for macroscale shape changes, and microscale shape changes for macroscale material property changes.
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2017.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 258-274).
2017-01-01T00:00:00ZVisual urban sensing : understanding cities through computer visionhttp://hdl.handle.net/1721.1/109656
Visual urban sensing : understanding cities through computer vision
Naik, Nikhil (Nikhil Deepak)
This thesis introduces computer vision algorithms that harness street-level imagery to conduct automated surveys of the built environment and populations at an unprecedented resolution and scale. We introduce new tools for computing quantitative measures of urban appearance and urban change. First, we describe Streetscore, an algorithm that quantifies how safe a street block looks to a human observer, using computer vision and crowdsourcing. We extend this work with an efficient convolutional neural network-based method that is capable of computing several perceptual attributes of the built environment from thousands of cities from all six inhabited continents. Second, we introduce a computer vision algorithm to compute Streetchange-a metric for change in the built environment-from time-series street-level imagery. A positive Streetchange is indicative of urban growth; while negative Streetchange is indicative of decay. We use these tools to introduce new datasets. We use the Streetscore algorithm to generate the largest dataset of urban appearance to date, which covers more than 1 million street blocks from 21 American cities. We use the Streetchange algorithm to also generate a dataset for urban change containing more than 1.5 million street blocks from five large American cities. These datasets have enabled research studies across fields such as economics, sociology, architecture, urban planning, and public health. We utilize these datasets to provide new insights on important research questions. With the dataset on urban appearance, we show that criminal activity has a robust positive correlation with the spatial variation in architecture within neighborhoods. With the dataset on urban change, we show that positive urban change occurs in geographically and physically attractive areas with dense, highly-educated populations. Taken together, the tools, datasets, and insights described in this thesis demonstrate that computer vision-driven surveys of people and places have the potential to massively scale up studies in social science, to change the way cities are built, and to improve the design, execution, and evaluation of policy and aid interventions.
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2017.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 122-131).
2017-01-01T00:00:00ZGround truth in ultra-dense neural recordinghttp://hdl.handle.net/1721.1/109655
Ground truth in ultra-dense neural recording
Allen, Brian D. (Brian Douglas)
While biologists routinely record neural activity with multi-electrodes, spike sorting-- the process of attributing spikes to particular neurons-- remains a challenge that typically requires human curation. Due to technical limitations, there have been very few multi-electrode recordings done in concert with techniques such as patch clamp, which report the "ground truth" voltage state of a single neuron in a population. Such recordings would allow for the direct evaluation of spike sorting, which in turn could lead to further development and refinement of spike sorting methods. We developed a technique to establish a whole-cell or cell-attached patch recording in a cortical neuron of an awake or lightly anesthetized head-fixed mouse, with simultaneous extracellular recording of the same neuron and its neighbors with arrays of close-packed, "ultra-dense," electrodes (64-256, 9 x 9[mu]m electrodes spaced 2[mu]m apart on a shank). Our recordings constitute ground truth for spike sorting evaluation, and allow for the direct evaluation and improvement of an algorithm for automatic spike sorting that benefits from high electrode density relative to neuron packing density. Using this technique we show the patch-triggered extracellular waveforms of neurons at a high level of granularity distributed across cortex, and give a glimpse into the spiking activity of the network surrounding a patched neuron in vivo. We explore the dataset generated with this technique and discover a spike-bursting trajectory exhibiting apparent spike-frequency adaptation. This bursting trajectory was readily apparent in deep but not shallow cortical neurons in patch recordings, but was somewhat obscured in extracellular recordings, where spikes from neighboring neurons may overlap in time to contribute "noise." We show how this trajectory can be easily seen in a high-amplitude extracellular recording, and propose how it may be accentuated in lower amplitude recording through the use of blind source separation.
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2017.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 64-73).
2017-01-01T00:00:00ZPaper electronics : circuits on paper for learning and self-expressionhttp://hdl.handle.net/1721.1/109617
Paper electronics : circuits on paper for learning and self-expression
Qi, Jie, Ph. D. Massachusetts Institute of Technology
In this dissertation, I explore the theme of wonder in technology, learning and self-expression through the lens of paper electronics, which is circuit building on paper using conductive tapes and circuit components as electronic craft materials. This new medium blends the interactive functionality of electronics with the expressive flexibility of the paper medium. I present an overview of the paper electronics medium as well as its extension in the form of electrified books, books with circuitry integrated with its pages and spine. I then described the design of a paper electronics toolkit called circuit stickers and how this toolkit was deployed through a company called Chibitronics. Finally, through the circuit stickers toolkit, I investigate and evaluate the paper electronics medium as a learning tool and approach, expressive medium and method to engage more diverse communities in technology creation. These investigations show that paper electronics has indeed impacted learners, educators and creators across many backgrounds and disciplines. It has enabled educators to teach a broad range of subjects and skills in new ways. Artists have used paper electronics to explore electricity and interactivity for self-expression, demonstrating the aesthetic flexibility and expressive potency of this medium. Finally, it has engaged creators from diverse communities and backgrounds including educators, Makers, and crafters. It enables not only new approaches to learning and creating technology, it also engages new types of creators in inventing surprising technological artifacts--ones that inspire new experiences, objects and opportunities for wonder.
Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2016.; This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.; "September 2016." Cataloged from student-submitted PDF version of thesis.; Includes bibliographical references (pages 148-156).
2016-01-01T00:00:00Z